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Publications

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Revised age and regional correlations of Cenozoic strata on Bat Mountain, Death Valley region, California, USA, from zircon U-Pb geochronology of sandstones and ash-fall tuffs

Basin analysis and tectonic reconstructions of the Cenozoic history of the Death Valley region, California, USA, are hindered by a lack of volcanic (tuff) age control in many stratigraphic successions exposed in the Grapevine and Funeral Mountains of California, USA. Although maximum depositional ages (MDAs) interpreted from detrital zircon U-Pb data may be a promising alternative to volcanic ages
Authors
Theresa Maude Schwartz, Amanda (Kate) Souders, Jens-Erik Lundstern, Amy K. Gilmer, Ren A. Thompson

Insights from the Alabama Hills into Mesozoic magmatism and tectonics in eastern California

New zircon U-Pb ages for the Alabama Hills Granite in Owens Valley, eastern California, range from 103 to 102 Ma, nearly 20 Ma older than previously published zircon ages. The data preclude previously implied links between the pluton and the adjacent Late Cretaceous Mount Whitney Intrusive Suite. Geochronologic and isotopic data indicate a connection between the Alabama Hills Granite and leucogran
Authors
Ryan Edward Frazer, Sean P. Gaynor, Drew S. Coleman, Jennifer M. Wenner

The National Cooperative Geologic Mapping Program’s U.S. GeoFramework Initiative — Delivering a digital database of geologic map information by 2030

The U.S. Geological Survey's National Cooperative Geologic Mapping Program's U.S. GeoFramework Initiative responds to Congressional direction to implement the National Geologic Map Database Phase Three. The U.S. GeoFramework Initiative aims to create and deliver a new digital geologic framework of the United States by 2030. This Fact Sheet outlines the collaborations needed and plans taken to achi
Authors
Jenna L. Shelton, William Andrews, Joseph Colgan, Samuel Johnstone, David R. Soller, Richard Berg, Donald S. Sweetkind, Kristine L. Zellman, John Brock, Kate Ritzel

A complex record of last interglacial sea-level history and paleozoogeography, Santa Rosa Island, Channel Islands National Park, California, USA

Studies of marine terraces and their fossils can yield important information about sea level history, tectonic uplift rates, and paleozoogeography, but some aspects of terrace history, particularly with regard to their fossil record, are not clearly understood. Marine terraces are well preserved on Santa Rosa Island, California, and the island is situated near a major marine faunal boundary. Two p
Authors
Daniel R. Muhs, Lindsey T. Groves, Kathleen R. Simmons, R. Randall Schumann, Scott A. Minor

The Seamless Integrated Geologic Mapping (SIGMa) extension to the Geologic Map Schema (GeMS)

Geologic maps are the fundamental building blocks of surface and subsurface three-dimensional geologic framework models of the Earth’s crust. However, as the production and availability of geologic map databases continues to increase, inconsistent data models and the lack of synthesized, national geologic map data at scales appropriate for informed decision making negatively affect the functional
Authors
Kenzie J. Turner, Jeremiah B. Workman, Joseph Colgan, Amy K. Gilmer, Margaret E. Berry, Samuel Johnstone, Kathleen F. Warrell, Marieke Dechesne, D. Paco VanSistine, Ren A. Thompson, Adam M. Hudson, Kristine L. Zellman, Donald S. Sweetkind, Chester A. Ruleman

Can we avert an Amazon tipping point? The economic and environmental costs

The Amazon biome is being pushed by unsustainable economic drivers towards an ecological tipping point where restoration to its previous state may no longer be possible. This degradation is the result of self-reinforcing interactions between deforestation, climate change and fire. We assess the economic, natural capital and ecosystem services impacts and trade-offs of scenarios representing moveme
Authors
Onil Banerjee, Martin Cicowiez, Marcia N. Macedo, Ziga Malek, Peter H. Verburg, Sean Goodwin, Renato Vargas, Ludmila Rattis, Kenneth J. Bagstad, Paulo M. Brando, Michael T. Coe, Christopher Neill, Octavio Damiani Marti, Josue Avila Murillo

GCPs free photogrammetry for estimating tree height and crown diameter in Arizona cypress plantation using UAV-Mounted GNSS RTK

One of the main challenges of using unmanned aerial vehicles (UAVs) in forest data acquisition is the implementation of Ground Control Points (GCPs) as a mandatory step, which is sometimes impossible for inaccessible areas or within canopy closures. This study aimed to test the accuracy of a UAV-mounted GNSS RTK (real-time kinematic) system for calculating tree height and crown height without any
Authors
Morteza Pourreza, Fardin Moradi, Mohammad Khosravi, Azade Deljouei, Melanie K. Vanderhoof

Geochemical evidence for diachronous uplift and synchronous collapse of the high elevation Variscan hinterland

Competing end-member models for the late Paleozoic Variscan orogeny (ca. 360-290 Ma) alternatively suggest moderate 2-3 km elevations underlain by relatively thin crust (55 km) that supported high 4-5 km elevations. We tested these models and quantified the crustal thickness and elevation evolution of the Variscan orogeny using igneous trace element geochemical proxies. The data suggest that thick
Authors
Ian William Hillenbrand, Michael L. Williams

Contemporary (1984–2020) fire history metrics for the conterminous United States and ecoregional differences by land ownership

Background: Remotely sensed burned area products are critical to support fire modelling, policy, and management but often require further processing before use.Aim: We calculated fire history metrics from the Landsat Burned Area Product (1984–2020) across the conterminous U.S. (CONUS) including (1) fire frequency, (2) time since last burn (TSLB), (3) year of last burn, (4) longest fire-free interv
Authors
Melanie K. Vanderhoof, Todd Hawbaker, Casey Teske, Joe Noble, Jim Smith

Geologic map of the Mount Evans quadrangle, Clear Creek and Park Counties, Colorado

The Mount Evans 7.5’ quadrangle lies in Park and Clear Creek counties, Colorado, about 60 km west of Denver. The highest elevation in the quadrangle is 14,265 ft (4,348 m) at the top of Mount Evans. The lowest is at about 9,200 ft (2,804 m) on Guanella Pass Road at the southern edge of the quadrangle. Bedrock directly underlies most of the map area, with surficial deposits primarily in the valleys
Authors
Logan Powell, Asha A. Mahatma, Yvette Kuiper, Chester A. Ruleman

A multiscale approach for monitoring groundwater discharge to headwater streams by the U.S. Geological Survey Next Generation Water Observing System Program—An example from the Neversink Reservoir watershed, New York

Groundwater-stream connectivity across mountain watersheds is critical for supporting streamflow during dry times and keeping streams cool during warm times, yet U.S. Geological Survey (USGS) stream measurements are often sparse in headwaters. Starting in 2019, the USGS Next Generation Water Observing System Program developed a multiscale methods and technology testbed approach to monitoring groun
Authors
Martin A. Briggs, Christopher L. Gazoorian, Daniel H. Doctor, Douglas A. Burns

Tectonic subsidence modeling of diachronous transition from backarc to retroarc basin development and uplift during Cordilleran orogenesis, Patagonian-Fuegian Andes

Backstripped tectonic basin subsidence histories are critical for interpreting phases of lithospheric deformation and paleoenvironmental change from the stratigraphic record. This study presents new subsidence modeling of the Rocas Verdes Backarc Basin (RVB) and Magallanes-Austral retroarc foreland basin (MAB) of southernmost South America to evaluate along-strike changes in tectonic subsidence re
Authors
Rebecca A. VanderLeest, Julie C. Fosdick, Matthew A. Malkowski, Brian W. Romans, Matías C. Ghiglione, Theresa Maude Schwartz, Zachary T. Sickmann